The present invention relates generally to a method of making a resilient cast by using impression material to fill any mold, such as an impression of an enucleated eye socket, an impression of the oral cavity, an impression of the tissue bearing surface of a denture, or any other mold in which it would be advantageous to have a resilient model on which to accomplish work. More specifically, the invention relates to the repair, fabrication and correction of occlusal discrepancies in dentures using an impression material to make a resilient cast.
The inconvenience and discomfort associated with dentures has to a large degree been minimized with the advancement of modern dentistry. However, most procedures relating to the repair of dentures are costly, time consuming and have not kept pace with the advancements in dentistry.
The traditional process of repairing a broken denture dates from the conception of using acrylic resin for denture construction. This repair process consists of temporarily luting the broken pieces into apposition prior to making a plaster cast to index the broken pieces. The broken edges are then ground to receive quick setting repair acrylic. The broken pieces may be removed and replaced on the cast after the broken edges have been prepared to receive repair acrylic. This procedure is complicated and rendered ineffective if the denture has undercuts whereby the denture is locked to the unyielding cast and cannot be removed. This problem can be partially overcome by blocking out the large undercuts in the denture with wet tissue paper before pouring the plaster. If the denture cannot be removed from the cast, it must be prepared on the cast by grinding along the broken edges. An inadequate preparation usually results in the preparation of a ditch to receive the repair acrylic. In addition to a less than ideal preparation, there is a danger of plaster contaminating the repair acrylic. Further, another problem associated with traditional methods is the danger of mutilating the cast if the denture is ground on the cast, resulting in defects on the tissue surface of the denture.
With regard to the fabrication of dentures, dentures that are inserted immediately following extraction of teeth are traditionally fabricated without regard to the shape or position of the teeth that are being replaced. In other words, the immediate denture is constructed by cutting off the plaster or artificial stone teeth from their cast and proceeding to fabricate a denture as if it were a normal edentulus case. There are several disadvantages to this procedure. For example, the occlusion is never exactly correct which causes non-stable dentures that produce sore spots and entail much time spent on equilibrating the denture. Tissue recovery material is normally used as the healing process changes the topography of the mouth. After complete healing, the intermediate denture must be relined or a complete new denture must be made to satisfy the criteria of an acceptable denture. In spite of the shortcomings of intermediate dentures, there are occasions when it is necessary or desirable not to use a laboratory "permanent" denture. The temporary denture is made quickly in the office and can be a valuable transitional denture during the healing period following surgery. If the denture duplicates the same occulision, the same vertical dimension and feels the same as the natural teeth, the patient will become conditioned to wearing a denture very quickly. After healing takes places, a "permanent denture" can be made that does not have to be relined so soon. A temporary intermediate denture possessing these qualities has heretofore been unavailable prior to applicant's invention.
Another problem experienced by denture wearers are sore spots caused by occlusal discrepancies in the patient's bite, in which premature cuspal contact causes shifting of the dentures, applying localized pressure to the oral tissue. Procedures are often performed by the dentist in an effort to quickly and immediately address the patient's discomfort. Correcting the occlusion is usually done by equilibration of the prematurities in the mouth. This method possesses many shortcomings, since the mouth is dark and wet and the procedure is time consuming causing the patient to become tired, resulting in a false bite. The dentures have a tendency to move, also giving false markings. The equilibration would be better achieved by transferring the dentures from the patient's mouth to an articulator, however there are currently several problems involved with this procedure. For example, original casts used for processing the dentures usually have been destroyed, and if present the dentures could not be made to fit them accurately. Plaster of paris cannot be used to mount the dentures to the articulator because most articulators require a thick base on the cast of the dentures which must be attached to the articulator. If it were possible to use plaster directly to form a cast in the denture the same problems would exist at removing and replacing the denture as previously described.
It is therefore an object of the present invention to provide for accurate and fast methods of denture fabrication, repair and equilibration procedures to eliminate or substantially minimize the above mentioned and other problems and limitations typically associated with current denture technology.